Positive displacement rotary pumps



11 Sheets-Sheet 1 AGENT E5? L l I "74 NI III IIIIIII I -J I I I I I 1 II I I I IlII I I L F N 5?, I I J INVENYOR JOHN N HINCKLEY March 7, 1967J. N. HINCKLEY POSITIVE DISPLACEMENT ROTARY PUMPS Filed Oct. 25, 1965 Mah'7, 9 7 J. N. HINCKLEY POSITIVE DISPLACEMENT ROTARY PUMPS 11Sheets-Sheet Filed Oct; 23, 1965 INVENTOR.

' JOHN N. HINCKLEY AGENT March 7, 1967 J. N. HINCKLEY 3,307,488

POSITIVE D ISPLAGEMENT ROTARY PUMPS Filed Oct. 23, 1965 ll Sheets-Sheet5 FIG. 5

INVENTOR.

\JOHN N. HlNCKLEY AGENT March 7, 1967 J. N. HINCKLEY 3,307,488

POSITIVE DISPLACEMENT ROTARY PUMPS Filed Oct. 23, 1965 ll Sheets-Sheet4L INVENTOR.

JOHN N. HINGKLEY AGENT March 7, 1967 J. N. HINCKLEY POSITIVEDISPLACEMENT ROTARY PUMPS Filed Oct. 23, 1965 11 Sheets-Sheet 5 .Qfi

1T? .411) F1. M12

6 s w L H N N M J March 7, 1967 N. HINCKLEY 3,307,488

POSITIVE DISPLACEMENT ROTARY PUMPS Filed Oct. 23, 1965 11 Sheets-Sheet 6I32 JOHN N. HINCKLEY FIG,I7 v

AGENT INVENTOR.

March 7, 1967 J. N. HINICKLEY 3,307,488

POSITIVE DISPLACEMENT ROTARY PUMPS Filed Oct. 23, 1965 Y 11 Sheets-Sheet7 53C 67 IC 49C 14C March 7, 9 7 J. N. HINCKLEY 3,307,488

POSITIVE DISPLACEMENT ROTARY PUMPS ll Sheets-Sheet 8 Filed Oct. 23, 1965FIG. 20

INVENTOR. JOHN N. HINCKLEY March 7,' 1967 J. N. HINCKLEY POSITIVEDISPLACEMENT ROTARY PUMPS 'Fil ed Oct. 23, 1965 ll Sheets-Sheet 9 JOHNN, H/NCKLEV INVENTOR.

March 7, 1967 J. N. HINCKLEY 3,397,488

POSITIVE DISPLACEMENT ROTARY PUMPS Filed Oct. 25, 1965 1 1, Sheets-Sheet10 JOHN H. H/NCKLEV INVENTOR.

AGENT.

Patented Mar. 7, 1967 3,307,488 POSITIVE DISPLACEMENT ROTARY PUMPS JohnN. Hinckley, 16052 Leflingwell Road, Whittier, Calif. 90603 Filed Oct.23, 1965, Ser. No. 503,628 26 Claims. (Cl. 103124) This application is acontinuation-in-part of the application of John N. Hinckley, Serial No.158,662, filed December 12, 1961, now Patent No. 3,240,157 forimprovements in rotary pumps.

The invention pertains more particularly to rotary pumps of the positivedisplacement type used for fluids, mixtures and semi-solids, such, forexample, as those required by the food and dairy industries for pumpingmilk, cottage cheese and other flowable products.

The pumps described in the present application embody many improvementsover those illustrated and described in the Hinckley patents, No.2,717,555 and No. 2,882,828, which issued on September 13, 1955 andApril 21, 1959, respectively.

In pumps of the type with which we are here concerned, extremesanitation and cleanliness are prime requirements, and it is highlyimportant that the design be such that the cleaning may be easily andquickly accomplished. In accordance with these requirements, it isdesirable, among other things, that narrow crevices, sharp corners anddeep holes be avoided in the design.

In keeping with the aforementioned considerations, the principal objectsof the invention are to produce a pump for liquids, semi-solids andmixtures of solids and liquids that is efiicient and relativelyinexpensive to manufacture, and to provide a design that will permit thepump to be easily and thoroughly cleaned in place, as by flushing, ormanually cleaned after only partial disassembly.

In order to achieve these ends, the invention has the followingsubsidiary objects.

(1) The provision of an efiicient seal between the liquid-containingcavity of the pump and the drive-shaft and its bearings;

(2) The provision of a rotor and a driving means for the rotor of suchdesign that a bearing is required for only one end of the shaft; r I

(3) The provision of simple and effective means for keying :a removablerotor to the drive-shaft;

(4) The provision of a rotor and a drive-shaft of such design that therotor may be sealed off at one end to prevgnt fluid from getting betweenthe rotor and the drives a (5) The provision of a pump of the typedescribed in which the axial thrusts on the rotor produced by eitherpressure or vacuum will always be in the same axial direction in orderto eliminate end play and vibration;

(6) The provision of a tolerance accumulation device that may beadjusted to compensate for all tolerance v-ariations in the componentsand that will always receive the forces directed against the rotor bythe vacuum or hydraulic pressure of the material being pumped;

(7) The provision of clean-out slots in the end plates of the rotorhousing of such design that any of the material being pumped that mayget between the rotor and the end plates may easily be flushed out;

(8) The provision of a pump of such design that tapered roller hearingsor other thrust bearings will absorb all the end thrust that is exertedagainst the aforementioned tolerance accumulation device;

(9) The provision in a pump of the type described in which oscillatingarms similar to those described in the previously mentioned Hinckleypatents may be more accurately positioned in the pump casing;

(10) The provision of means whereby wear between the said oscillatingarms and the adjacent end plates may be reduced to a minimum.

This invention possesses many other advantages, and has other objectswhich may be made more clearly apparent from a consideration ofillustrative embodiments of the invention. For this purpose suchembodiments are shown in the drawings accompanying and forming part ofthe present specification. These forms will now be described in detail,illustrating the general principles of the invention; but it is to beunderstood that this detailed description is not to be taken in alimiting sense, since the scope of the invention is best defined by theappended claims.

In the figures:

FIGURE 1 is a side elevation of one form of the pump showing thesimplicity of the impeller casing and the shaft housing, together withcertain internal parts in phantom;

FIG. 2 illustrates a method of journaling the oscillating .vane mountingshaft in the end plates of the pump housing;

FIG. 3 is a front end view of the pump illustrated in FIG. 1, showingcertain parts in phantom, including grooves on the inner surfaces of theend plates to cooperate with cavities in the ends of the impellers forentrapping some of the material being pumped so that this material mayact as a cushion to maintain a hydraulic balance of the impellers forminimizing or removing end P y;

FIG. 4 is a partial cross-section taken on line 4-4 of FIG. 3, showingthe cooperation of one of the aforementioned grooves with the cavity inthe adjacent impeller;

FIG. 5 is a cross-section taken on line 5-5 of FIG. 1;

FIG. 6 is anisometric view, of a removable partition that is a componentof the structure shown in FIG. 5;

FIG. 7 is a partial longitudinal section through the rear plate of thepump casing and the adjacent portion of the bearing housing, showing thecooperation between the two and a method of producing an eifective sealaround the shaft between the casing and the bearings for the shaft;

FIG. 8 is an isometric view of a rotor assembly showing two impellerswith a separating disc and certain other structural features of therotor;

FIG. 9 is a section taken on line 99 of FIG. 8;

FIGS. 10, 12, 14 and 15 show different positions of the rotor and theassociated oscillating arm during each revolution of the rotor in thepumping cycle;

FIG. 11 is a broken-away view of a portion of the rotor housing of oneembodiment of the invention, showing one position of each of the twovanes that cooperate with the rotors, not shown;

FIG. 12 is described in connection with FIG. 10;

FIG. 13 is a longitudinal section, partly broken away of one species ofmy invention in which novel and multiple sealing means are used betweenthe impeller and the specially formed driving shaft employing a uniquearrangement for keying the shaft and rotor;

FIGS. 14 and 15 are described in connection with FIG. 10;

FIG. l6is a broken-away isometric view of the outer portion of thedrive-shaft to drive the impeller assembly of FIG. 8;

FIGS. 17 and 18 are illustrations of alternative mem- 3 bers forimposition between compression springs such as those shown in FIG. andthe associated oscillating partitions or vanes;

FIG. 19 is a longitudinal section through another embodiment of theinvention using an impeller that is completely covered with rubberexcepting for the central bore that receives the shaft. This figure alsoillustrates modified sealing arrangements for preventing the fluid fromgetting into the shaft bearings;

FIG. 20 illustrates the use of a combination dowel and screw forattaching the end plates to the central housing;

FIG. 21 is a side elevation, partly broken away, of

another embodiment of the invention in which all pressure or vacuumforces that are exerted axially on the rotor are exerted in the sameaxial direction and in which all tolerance variations are compensatedfor by a novel tolerance accumulation device;

FIG. 22 is a right end view of the pump shown in FIG. 21 with the rightend plate removed;

FIG. 23 is a section taken substantially on line 23-23 of FIG. 21;

FIG. 24 is a section taken substantially on line 2424 of FIG. 22; and

FIG. 25 is an exploded view of the pump shown in FIG. 21.

FIG. 26 is a side elevation, partly cut away, of an embodiment utilizinga tapering drive shaft.

FIG. 27 is a front elevation, partly cut away, of the embodiment shownin FIG. 26.

FIGS. 1 to 9, 11, 13, and 16 to 20, are identical to the figures bearingthe same numbers in the parent application, While FIGS. 10, 12, 14 and15 illustrate the action of the rotor.

For convenience in referring to the components of the presentlypreferred embodiment which are described for the first time in theinstant application, they have been given reference numerals 200 higherthan the corresponding parts in the embodiments that were illustrated inthe parent application.

The components shown in FIGS. 10, 12, 14 and 15, which are common tovarious illustrative embodiments of the invention, have been givenreference numerals 300 higher than were used for their counterparts inthe parent application.

In the embodiments of the invention shown and described herein, agenerally cylindrical casing 1 is closed at opposite ends by flat plates2 and 3 to form a chamber for the principal parts of the pump, and thehousing 4 supports and protects the bearings for the drive shaft. Thecasing 1 has an inlet port 7 and an outlet port 8.

For simplicity of manufacture and to provide an easily cleanableinterior surface, it is desirable to use a casing similar to that shownin FIG. 5, where the outer end plate has been removed to showtheinterior construction. It will be observed that a cross-section of thecasing reveals an oblong body with an upper semi-cylindrical bore 9 andan overlapping lower semi-cylindrical bore 10. The rotor 11 fits in thelower bore 10. The rotor may be generally ,of the construction disclosedin the earlier Patents No.

2,717,555 and No. 2,882,828, both of which have been mentionedpreviously.

A somewhat improved rotor, shown in an isometric view in FIG. 8, has acosine shape and comprises two impellers 12 and 13 disposed at rightangles to each other with a circular disc 14 between them. Both of theseimpellers are of symmetrical design, and each has a short diameter and along diameter that are at right angles to each other to form two lobes.Impeller 12 comprises lobes 15 and-15a, and impeller 13 has two lobes 16and 16a, FIG. 5.

At least the periphery of each of these impellers is formed of arubber-like material or a plastic substance and the entire rotor iskeyed to a drive shaft 18 in any of a variety of ways. One suitablekeying arrangement is illustrated in FIGS. 5, 8 and 16. It will beobserved that the center opening in impeller 12 is not round but thatthe recess has three arcuate sides 17, 17a and 17b, whose radii are eachgreater than the greatest distance from the associated side to the axisof the impeller. This threearcuate-sided opening may communicate with acylindrical opening in impeller 13. The reduced outer end 20 of thedrive shaft must of course have arcuate sides, as illustrated in FIG. 16to conform with the arcuate sides 17, 17a and 17b of the recess in theouter end of the double impeller structure. In assembly, the end of therotor structure having the cylindrical opening must first be slippedover the end 20 of the drive shaft 18 and then over the round portion 19of the shaft.

The keying arrangement just described has the great advantage that allportions of the three-arcuate-sided part of the shaft are in drivingcontact with the contiguous portions of the recess bounded by sides 17,17a and 17b.

In the embodiment illustrated in FIG. 5, a removably mounted partition21, also shown in FIG. 6, extends from the upper interior surface orceiling of the pump to the disc 14 that is positioned between the twoimpellers. The surface 91 of this partition is parallel to the axis ofthe rotor.

This removably mounted partition constitutes an important improvementover the partition that is integrally formed in the corresponding upperportion of the pumps described in the earlier patents above mentioned.The upper surface of partition 21 is arcuately formed to match thearcuate upper inner surface of the pump and may be attached thereto byany convenient means.

The vane 22 constitutes a movable partition extending from thestationary partition 21 to the periphery of impeller 12. This vane isintegral with an arm 23 which terminates in a boss 24, and theconstruction is generally the same as the construction of thecorresponding movable vane member in the earlier patents above referredto. It will be understood that another similar vane, arm and hubstructure cooperates with partition 21 and the other impeller 13 on theopposite side of the circular disc 14all substantially as shown in theaforementioned earlier patents. Hub 24 and the corresponding hub thatcooperates with the other vane are mounted on a removable shaft 25, theends of which may be removably inserted in appropriate holes in the twoend plates, just as shaft 49 is mounted in the structure illustrated inFIG. 5 of the aforementioned Patent No. 2,882,828. A compression spring26 expands between extension 28 of partition 21 and the spring cup orcap 27 that pivots on the ball 131 integrally attached to arm 23. Itwill of course be understood that another identical spring cooperateswith the aforementioned other vane, arm and hub structure associatedwith impeller 13 on the opposite side of the central disc 14.

The rear surface 29 of partition 2 is hollowed out as indicated in FIGS.5 and 6 in order to present a smooth surface to direct the inflowingsubstances from port 7 toward the impellers.

Inasmuch as the two impellers are at right angles to each other, it willreadily be understood that the two-cycle operation of each impeller isout of phase with that of the other. This means that the pressureexerted by the inflowing material against one side of disc 14 islikewise 90 out of phase with the pressureexerted against the oppositeside of the disc. In each case the pressure urges the disc and the wholerotor assembly toward the opposite end plate. This tends to createvibration. been introduced in the pump illustrated in FIGS. 3, 4, 5, 8and 9 to cushion the impellers and the end plates against thesepressures that tend to cause rhythmic oscillation of the impellerassembly along the shaft To effect such cushioning, continuous shallowrecesses 129 are provided in the end surfaces of the two lobes of eachimpeller, as illustrated in FIGS. 3, 4, 5, 8, 9 and 14, and twoelongated recesses 30 and 31, FIGS. 3 and 4, are provided in each of thetwo end plates. As the impellers Means have turn, the shallow recesses129 in the outer surfaces of the lobes traverse the elongated grooves orcavities 30 and 31 in each of the end plates. As each traversal begins,some of the milk or other fluid being impelled through the pump, becomesentrained between the end of the impellers and the inner surfaces of theend plates. This entrapped fluid acts as a cushion against theaforementioned longitudinal oscillation or vibration of the rotor orimpeller assembly. The elimination or reduction of this reciprocatingforce on the impeller assembly of course produces smoother and quieteroperation and increases the life of the pump.

It is of the utmost importance in pumps of the type with which we arehere concerned that the liquid or semiliquid material being impelled bekept from coming in contact with the shaft bearings. In the embodimentof the invention to which FIGS. 1 and 7 pertain, the drive-shaft may beprovided with a pair of bearings, such as bearings 5 in the bearing box46 of these figures and a second similar bearing (not shown) in box 47,FIG. 1. Both of these boxes may be integral with the housing 4. Endplate 2 of the pump casing has a central opening 48, to permit shaft 18to pass therethrough, as indicated in FIG. 7. The inner periphery ofthis central opening 48 is provided with an annular groove in whichnests an O-ring, quad-ring, or the equivalent. This ring 49 embracesshaft 18 and provides a barrier to prevent the material that is beingimpelled through the pump from passing through the opening 48.

In order to assure substantially perfect alignment of the bearing 5 andthe opening 48 with its trapped O-r ng 49 within the end plate 2, thesurface of the bearing housing that is adjacent to plate 2 is providedwith an annular boss or protrusion 50 that mates with an annular recess51 in plate 2 around the central opening 48. The annular boss 50 and thecavity 51 in plate 2 of course have mating contours; in fact, it ispreferable that the boss 50 have an abrupt shoulder to fit thecylindrical sides of the cavity 51 when the front surface 52 of thebearing housing is in firm contact with the adjacent surface of endplate 2. The snug fit of boss 50 Within cav ty 51 assures highlysatisfactory alignment of O-ring 49 w1th the shaft 18.

An additional, or second, barrier or resilient annular sealing member isalso provided. This is the rubber or leather ring 53 that hugs theenlarged section 54 of the shaft. A shaft seal back-up ring 55 isinterposed between the bearing seal 53 and the internal shoulder 56within the boss 50 of the bearing housing. Still a third seal isprovided by the neoprene or equivalent bearing ring 57 that also servesto hold the lubricant within the hearing and keep moisture out. Anotherbearing seal 58 is also employed on the opposite side of the bearing.

As an added safeguard against the passage of liquid from the interior ofthe pump casing into the bearing 5, an additional annular recess 59 isformed in the endplate 2. This recess communicates with a drainagechannel 6!), extending to the bottom of the pump casing. Any fluid thatescapes from the interior of the pump despite the sealing action of theO-ring 49 is almost entirely drained off by gravity through thepassageway 60 before reaching the bearing seals 53 and 57.

FIG. 13 illustrates another arrangement which the sealing provisionshave been carried a step further. In this embodiment of the invention,the shaft 18c is provided with an eccentrically disposed reduced end200, which fits in a sleeve 62 having a thick wall or bottom 63 at its.outer end. This thick Wall is drilled or bored eccentrioally so thatwhen the main portion of shaft 180 is fitting inside the relatively thinwalls of the sleeve 62, the eccentric reduced end of the shaft will fitin the eccentric mating opening 64 in the end of the sleeve. A disc 65is welded or cemented to the outer end of sleeve 62 to provide aleak-proof seal.

The rotor 66 is centrally apertured to fit over the sleeve 62 to whichit should be weldedor cemented. Any of the fluid being impelled throughthe pump by the rotor 66 can thus not reach the shaft 18c proper, butthe entire rotor assembly including the sleeve 62 may be movedlongitudinally with respect to the shaft 180. The eccentric reduced end20c fitting in the mating eccentric opening 64 avoids any relativeangular movement between the sleeve and the shaft and provides anexcellent keying arrangement whereby the shaft rotates the impellerassembly 66.

In this embodiment of the invention, the central opening in the endplate 1c is large enough to receive the sleeve 62, and a sealing ring490, which is the counterpart of the O-ring 49, FIG. 7, nests in anannular recess on the inner wall of the circular opening and fits snuglyagainst the sleeve 62. The leather or rubber-like ring 530 expandsbetween the periphery of the sleeve 62 and the inner sur face of theannular boss 67 that protrudes from the housing of the bearing 5c. Thebearing itself has the usual lubrication-retaining seals 57c and 58c andgrease fittings for proper lubrication. A drain opening 600 extends fromthe sleeve 62 to the bottom of the housing, forming a counterpart ofdrain 60 in FIG. 7, and any fluid from the pump that escapes by theO-ring 490 is mostly drained through the recess 600 without exerting anypressure against the resilient annular seal 530 that might tend to causethe fluid to bypass this second resilient seal.

Another important feature of the embodiment just described is the easewith which the pump may be assembled and disassembled. Dowels 70 and 71,FIG. 1, extending into both the end plate 2 and the casing 1, assure theperfect alignment of the casing with respect to this end plate, and asecond group of dowels 72 and 73 assure the similar alignment of theouter end plate 3 with respect to the casing. These dowels, however, maybe omitted if the oscillating partitions are supported in any of theWays illustrated and described herein, rather than as shown in theaforementioned earlier patents, and if some such means as thatillustrated in FIG. 7 is used to assure a perfect fit between thebearing housing and the casing in which the impellers are located. Longbolts 74, threaded on both ends, extend through the wall or body of thecasing 1 and also through the end plate 2 and are threaded into thefront wall or surface of the housing 4. The outer ends of the bolts 74receive the wing nuts 75. g

It will be seen that by removing these wing nuts, the front plate 3, thecasing 1, and the end plate 2 may all be successively removed from thebearing housing 4. The impeller assembly is easily slidable from thedriving shaft for cleaning purposes, and any of the vane and armassemblies may readily be dismantled regardless of whether the armassembly is spring loaded, magnetically loaded or held against theperipheries of the impellers by gravity.

FIG. 19 illustrates still other modifications in the rotor as well as inthe sealing means. The rotor is not formed of a resilient materialthroughout, but most of the exterior surface is coated with or formed ofa resilient material such as neoprene. A resilient substance 156 alsocompletely encases or coats the interior or cored portion excepting forthe central opening that receives and fits the drive shaft 18d.

Recess 30a corresponds to recess 30 in FIGS. 3 and 4. Recess 30b is thecooperating recess in the opposite end plate 30, whereby cushioningfluid is entrained by the opposite impeller. "This modification utilizesno recess in the end plates corresponding to recess 31 in FIG. 3, as ithas been found that a better hydraulic balance is obtained with only thesingle set of oppositely disposed recesses in the end plates.

FIG. 19 also illustrates .a different form of seal between the impellercasing and the bearing housing. A nonrotating ring 134 that may besuitably formed of carbon or a ceramic material surrounds the shaft 18dand is held in spaced relationship thereto by means of a gasket ring 135having an L-shaped cross-section. Ring 135 nests in an annular recess390 in the end plate 1a. Ring 136 fits shaft 18d closely and is keyed torotate therewith. An O-ring 137 nests in an appropriately formed recess61 in the impeller 12d and presses on the sloping side of ring 136,urging the opposite vertical face of ring 136 against the ceramic orcarbon ring 134. If ring 134 is formed of carbon, ring 136 will operatevery satisfactorily therewith if it is formed of a ceramic, but if ring134 is molded from a ceramic material, then it is well to use carbon forring 136. Carbon is currently used for this purpose because it has a lowcoefficient of friction, dissipates heat readily, and can stand hightemperatures without distortion. Other metals, or even a plastic, mayalso be used for this purpose if they have the aforementionedcharacteristics.

Inasmuch as both the sloping and vertical faces of ring 136 must becapable of making a sealing contact, it is important that they be keptfree from blemishes such as can occur if the ring is dropped on a hardsurface. Accordingly, a resilient retainer or guard ring 138 is providedto keep ring 136 from being accidentally brushed from shaft 18d duringdisassembly and to prevent its slipping from the shaft if the pump istilted at too great an angle when the rotor is not on the shaft. Ring138, the retainer ring, is held by its own resilience in groove 139'.

The substantially L-shaped resilient ring 140 fits closely against shaft18d and serves to throw off any fluid that passes rings 136 and 134 andthe gasket 135, thus preventing such fluid from reaching the vicinity ofthe bearings. An annular casting 141 has a radially extending inner lipthat is interposed between the outer portion of ring 140 and anothersealing assembly that comprises parts 142, 143 and 146. Part 142 is anannular ring having an L-shaped cross-section. Into this is cemented aresilient rubber-like ring 143. The garter-ring 146 urges the portion ofring 143 immediately adjoining the periphery 144 of the enlarged section145 of the drive shaft into sealing engagement therewith. Fluid that maypass the sealing members to the right of ring 140 and which is thrownoutward by this ring is received in the annular recess 147 whichcommunicates with the drain described in connection with previouslydiscussed figures.

FIG. 20, as already mentioned, illustrates a combination bolt and dowelarrangement that not only assures the proper positioning of the endplates 2c and 30 with respect to the casing 1c, but also secures thesemembers to the bearing housing 4c. Perhaps the most important feature ofthis arrangement, however, is that it permits the casing to be reversedwith respect to the end plates for either clockwise or counterclockwiseoperation of the rotor, thus allowing the fiuid to be pumped therethrough in whichever direction may be most convenient for the particularinstallation.

The threaded end 148 of the dowel-bolt 149 is screwed into thecorrespondingly threaded hole 150 in the bearing housing 4d. A bolt hole153 extends all the way through the wall of casing 1d. As shown in thefigure, it has a counterbore 151 on the left side to match the largediameter 154 of the bolt 149. An appropriate opening through end plate2d also closely fits the enlarged portion 154, which constitutes thedowel section of the dowel-bolt 149.

In assembly, the bolt 149 is first inserted through the plate 2d andthen screwed into the bearing housing 4d. The portion of the bolt 149 tothe right of the enlarged section 154 is reduced in diameter to permitthe casing 1 d to be slipped over the bolt, whose smaller diameter fitsthe narrower opening in the housing 1d between the two counterbores 152and 152. With this arrangement, it will readily be seen that the end ofthe casing that normally adjoins end plate 3d could be reversed andplaced against the end plate 2d, thus permitting a reversal of thepositions of the inlet and outlet ports of the pump.

After the end plate 3d has been slipped over the outer end of the bolt,the wing nut 155 is threaded thereon and tightened into position to holdthe entire assembly firmly together.

It will of course be understood that other dowel-bolts such asdowel-bolt 149 are used in other locations around the end plates andpump casing to hold them firmly together. The required plurality ofbolts is indicated in FIG. 19, where two such bolts are shown with theirassociated wing nuts 155.

FIGS. 21 to 25 illustrate an embodiment of the invention that is animprovement over those hereinbefore described. It perhaps most closelyresembles the structure shown in FIGS. 13 and 19. The drive shaft 218,FIGS. 21 and 22, is the counterpart of the drive shaft of FIGS. 13 and18d of FIG. 19, and the eccentric end portion 220 corresponds to thesimilar end portion 200 of FIG. 13.

The impeller 212, which is a counterpart of the impeller 120 of FIG. 19,has a casing 356 of natural or synthetic rubber. This casing is recessedat 329 excepting for a central button portion 357 which protrudes about.002" beyond the outer rim that surrounds the recess 329. Thisprotruding central portion 357 abuts against the inside surface of theend plate 2030.

The impeller 212 has an opening 264 therein to receive the eccentric endportion 220 of the drive shaft 218, but the end 220 does not bottom inthe recess 264, for reasons that will hereinafter become apparent.

The core 358 of the impeller 212 is completely encased by artificial orsynthetic rubber or plastic excepting where the core engages theperiphery of the drive shaft and the outer end that faces the end plate2020. The core 358 has an annular recess 360 filled with the sameresilient material that surrounds the core. The outer portion of theimpeller and the core are thus interlocked, as well as bonded together.

The rotor has an annular L-shaped recess 361 in the outer end thereofcommunicating with the periphery of the drive shaft 218. An O-ring 337nests in this recess. This ring abuts against the sealing ring 336 whichsurrounds the drive shaft 218 and is keyed thereto in a manner later tobe explained. The vertical side of the sealing ring engages thestationary ring 134 which at present is preferably formed of carbon or aceramic material. This ring nests in the gasket 335. The ring 334 andthe gasket are the counterparts of the corresponding components in thepreviously described embodiments.

The hydraulic pressure or vacuum of the material that is being pumpedexerts a pressure on the right end surfaces of the impeller thus forcingthe O-ring 337 tightly against'the sloping surface of the sealing ring336, pressing it against the stationary ring 334, as hereinbeforedescribed in connection with the similarly numbered counterpartspreviously described. It is important, however, that the end thrust beborne primarily by the thrust bearings in the bearing housing 204. Inthe structure illustrated in FIG. 21, these are tapered roller bearings,but it will be readily understood by those skilled in the art that othertypes of thrust bearings may be substituted.

In order to direct the axial thrust against these bearings it is ofcourse essential that the pressure exerted against the impeller betransmitted to the shaft 218. In previously described embodiments, suchas that illustrated in FIG. 19, this thrust is directed against theeccentric reduced end of the drive shaft which bottoms in the recess ofthe impeller core, as perhaps best shown in FIG. 13. Great manufacturingprecision would obviously be required to so form the parts that thisbottoming occurs just when the sealing ring, such as ring 136 in FIG.19, is exerting the optimum pressure against the stationary ring 134.Variations in manufacturing tolerances make this a very difiicultcondition to obtain. Accordingly, a tolerance accumulation device 359,shown in FIGS. 21

r 9 and 22, is provided. With 'suitable adaptive variations that willreadily occur to those skilled in the art, this tolerance accumulationdevice may be used in all other embodiments of the invention.

The inner end or shank of this member 359 is provided with male threads362 that cooperate with female threads 363 in the main body portion ofthe shaft. These threads are coated with a suitable epoxy so that thefinal adjustment of the tolerance accumulation device may be maintained.The enlarged outer end 364 of the tolerance accumulation deviceprotrudes from the main body of the shaft for engagement with thevertical inner surface 366 of the rotor core 358. The head 364 of thetolerance accumulation device is recessed on one edge to provide a flatportion 366 to receive a special wrench for rotating the device in orderto screw it in and out of the end of the shaft for a precise adjustment.By means of suitable instruments which per se form no part of thepresent invention, the tolerance accumulation device is adjusted so thatits flat outer end 365 engages the vertical inner surface 366 of thecore when the compression forces on the O-ring 337 and the stationaryseal 334 are at their optimum value. Sufficient depth must be providedin the recess 264 to make sure that the reduced end 220 never engagesthe bottom of the recess and that the axial thrust of the impeller isalways received by the tolerance accumulation device which transmits itto the thrust bearings in the bearing housing 204.

The entire construction of the rotor assembly is such that it may beeasily and rapidly disassembled for cleaning and reassembled with equalcase. After removing the nuts 378 from the bolts 379, the end plate 2030may be withdrawn and the rotor 212 pulled from the drive shaft 218. jThe sealing O-ring 337 will usually remain in its L-shaped nest in theopen end of the rotor, but may easily be removed if desired.

The ring 336 has a nodule 377 on its inner surface that extends radiallytherefrom to engage the flat portion 382 on the shaft. This flat portioncooperates with the nodule for keying purposes in lieu of a conventionalkeyway. The ring 336 may he slipped from the shaft after first removingthe restraining O-ring 338. During reassembly, the ring 336 must ofcourse be oriented so that the nodule 377 engages the flat portion 382of the shaft. The O-rings 377 and 338 should then be replaced and therotor 212 slipped back over the end of the shaft with the reduceddiameter extreme end portion of the shaft extending into the recess 264within the core 358.

Structural features have been provided in the embodiment shown in FIGS.21, 22 and 23 to permit the pump to be flushed or cleaned withoutdisassembly. This practice has come to be known in the food industriesas cleanin-place, or simply CIP. For such cleaning, water is 'pumpedthrough the rotor housing 201 from the inlet opening 207 and thencethrough the outlet port 208 in the manner in which the food products arepumped therethrough, suitable cleaning chemicals being added to thewater, depending somewhat upon the nature of the residue from previouspumping operations that are to be removed from the pump.

Interconnecting passageways are provided to permit the cleaning fluid toreach the flexible O-ring 337 and the sloping sided sealing ring 336.Certain of these passageways are formed in the end plates 202a and 2030,end plate 2020 having a groove 383 above the central opening throughwhich the drive shaft passes and another groove 384 positioned below thecentral opening in the end plate. Both of these grooves are spaced andseparated from the central opening by solid portions of the end plate.Corresponding cleaning grooves 383a and 384a are provided in the outerend plate 2030. The recess 383a communicates with the recessed portion329 in the closed end of the rotor. This permits the cleaning fluid toflow from the groove 383a through the retends axially along the outsideof the shaft.

cess 329 and thence out of the recess 384a into the rotor chamber in thehousing.

The open end of the rotor 211 within the impeller 212 has a shallowrecess 329a surrounding the L-shaped recess 361 and communicatingtherewith. The recess 329a is bonded by the rim 386 of the impeller.Fluid may enter the groove 383 at any time, as it extends radiallybeyond the portions traversed by the impeller rim. The recess 329acommunicates with the sloping surface of the sealing ring 336 and withthe adjacent surface of the O-ring 337, and the fluid may flow aroundthe ring 336 to its opposite side Where the space adjacent theretocommunicates with the lower groove 384 in the end plate. This lowergroove is closed when the lobes of impeller 212 are in verticalalignment, but it is open to the region below the lobes when they aredisposed horizontally. Likewise, the cleaning groove 383a in end plate203:: is always open, and the lower groove 384 is open only when thelobes of impeller 213 are horizontally disposed. It should thus be clearthat the two lower cleaning slots 384 and 384a are open alternatelywhile the upper cleaning slots 383 and 383a are always open.

Still other novel features are included in the embodiment illustrated inFIGS. 21, 22 and 24, the latter figure being a section taken on line2424 of FIG. 22. This figure shows an improved construction for thereciprocating vanes, as well as for the structure by means of which theyare mounted. In the previously described FIG. 11, for example, the vaneswere mounted on a shaft 25a passing through a central internalprojection 39 of the main housing and into side portions 37 and 38thereof; and the hub of arm 40 of the vane 22a was confined between theportions 37 and 39 of the housing, while the hub of arm 41 of thecompanion vane was confined between the central support 39 and the outersupport 38 that holds the right end of the shaft 28 when these parts areoriented as they are shown in FIG. 11.

The arrangement shown in FIG. 24 is much easier to assemble anddisassemble than the structure just described. In this embodiment, thereis a central support 239 that is integral with the housing, but thereare no side or end support-s corresponding to the supports 37 and 38 ofFIG. 11. The single support 239 is adequate. The reciprocatingstructures 240 and 241 embodying the vanes 222 and 222a are integralrespectively with hubs 224 and 224a. These hubs, it will be observed,are offset with respect to the arms and the vanes, but inasmuch as eachhub abuts against the neighboring end plate and reaches only to thecentral support 239 rather than to the plane of the central disc 214that spaces the impellers, the offset arrangement of the hubs accuratelypositions the vanes 222 and 222a with respect to the impellers withwhich they individually cooperate. During assembly, the support shaft225 is inserted through the central support 239 and cemented or Weldedin place. The

oscillating structure 240. is then placed in position by sliding its hub224 over the end of the shaft 225. The arm 241 is similarly mounted.

The vanes 222 and 222a are held against the peripheries of impellers 213and 21 2 respectively by the springs 226 and the caps or bosses 227 thatride upon the balls 331 which are integral with the oscillating arm.This structure and the cooperation of the various elements making it uphas been described in connection with the mechanism ilustrated in FIG.5.

FIGS. 26 and 27 illustrate an embodiment utilizing a tapering driveshaft 218a. The core 258a of the rotor 211a has a tapered cavity thereinthat mates with the tapered drive shaft 218a.

In order to key the rotor 211a to the drive shaft 218a, a generallyV-shaped recess or keyway 387, FIG. 27, ex-

The bottom 388 of this keyway is curved in order to eliminate cornersthat impede cleaning. A companion key 389 is formed on the interior wallof the large cavity within the rotor core.

The drive shaft for this embodiment of'course requires no offset outerend such as the boss 220 in the previously described embodiment, and theabsence of this boss makes it possible to place the toleranceaccumulation device 359a in the exact center of the shaft, as shown inFIGS. 26 and 27. Inasmuch as this tolerance accumulation device is thesame in all other respects as that shown in the previously describedembodiment, additional structural details will not be described. Forsimilar reasons, reference to structural features of the rotor that areidentical in this embodiment to the corresponding features described inconnection with previously described figures are omitted from thepresent description.

Various modifications may of course be made from the embodimentshereinbefore described and in the components; in fact, any of theelements set forth in the appended claims may be omitted and replaced byother elements performing the same functions or the same functions plusadditional functions. Moreover, the location of components may bechanged or reversed without departing from the broad spirit of theinvention as embodied in the structures set forth in the appendedclaims.

The inventor claims:

1. In a rotary pump comprising a casing having a circular opening for ashaft and oppositely disposed inlet and outlet ports therethroughcommunicating with a chamber therein a portion of whose walls mostdistant from said ports are concentric with said opening, a combinationincluding: a drive shaft concentric with said opening extendingtherethrough into said chamber and terminating therein; a bearingstructure for said shaft disposed exteriorly of said chamber, the end ofsaid shaft within said chamber being free from support; a removableimpeller entirely closed at one end and having a recess in its other endthat slidably receives the unsupported end of the drive shaft; means'forkeying said impeller to said shaft for rotation therewith; said impellerhaving spaced peripheral portions that sweep said concentric portion ofsaid walls; and instrumentalities interposed between said ports fordirecting the inflow from said inlet port toward said concentric portionof the walls whereby said inflow may be moved along said portion of saidwalls toward said outlet port by said spaced peripheral portions.

2. The combination set forth in claim 1 in which the casing comprises acentral cylindrical section closed at its opposite ends by front andrear plates, said rear plate having the circular opening therein, and inwhich the impeller has a minimum diameter at right angles to a maximumdiameter to form opposite lobes that constitute the said spacedperipheral sections and in which the said instrumentalities includes apartition across the space between the ports, said partition extendingfrom one of said plates to the other and from the path traversed by saidlobes to a portion of the walls of the chamber opposite from those thatare concentric with said opening, said instrumentalities also includingan oscillating member pivotally carried by a support that is fixed withrespect to said casing, said oscillating member traversing the side ofsaid partition opposite from said inlet port and continuously bearingagainst the periphery of said impeller to close the varying gap betweenthe partition and the impeller as the impeller rotates.

3. The combination set forth in claim 1 in which the casing has anannular cavity therein concentric with said opening to provide ashoulder around the opening, said cavity communicating with said openingas well as with the inside surface of said casing, the impeller having aconcentric recess in the end thereof facing said opening, and to whichsaid combination is added sealing instrumentalities to prevent theescape through said opening of material being propelled through saidcasing by said spaced peripheral portions, said sealinginstrumentalities comprising: a resilient ring loosely surrounding saidshaft within said recess; an annular gasket mounted within said cavity;a first collar on said shaft between said gasket and said ring; a secondcollar closely surrounding said shaft between said first collar and saidring; said second collar having a first side engaging said first collarand said second collar so conically shaped that it may extend partiallywithin said resilient ring; said ring acting to force said collarsagainst said gasket when axial pressure is exerted on said impeller inthe direction of said opening.

4. The combination set forth in claim 1 in which the means for keyingthe impeller to the shaft for rotation therewith comprises: a projectionon the end of the shaft,

' the periphery of the projection having angularly spaced portionsthereon that vary from each other in their distances from the axis ofthe shaft, no portion on the periphery of said projection extendingbeyond the shafts periphery; and in which the recess in the impeller hasa first portion that slidably receives said shaft and a second portionthat matches, embraces and slidably receives said projection.

5. The combination set forth in claim 1 in which the drive shaft taperstoward its free end and has a concave groove extending longitudinallyalong its periphery from said free end, and in which the said recess inthe impeller is tapered to fit the taper of said shaft and so shapedthat a portion of the walls of the recess project internally to nestwithin said groove and key the impeller against angular movement withrespect to the shaft.

6. The combination set forth in claim 1 in which the bearing structurecomprises a thrust bearing and in which the open end of the recess inthe impeller is offset to form an annular shoulder within the open endof the impeller and to which said combination is added: a circularassembly surrounding said shaft between said shoulder and the portion ofthe casing surrounding said circular opening, said assembly comprising aresilient ring positioned against said shoulder; and a toleranceaccumulation device adjustably protruding from the end of the shaft,said tolerance accumulation device having male threads thereon inthreaded engagement with female threads in the shaft, the end of saiddevice being provided with means to facilitate its manual rotation foradjusting the extent of its protrusion; said device acting when suitablyadjusted to be engaged by the bottom of said recess and transmit anyforce applied to the closed end of the rotor to the shaft and thence tothe thrust bearing after said circular assembly has first begun to bearagainst said portion of said casing.

7. The combination set forth in claim 2 with the addition of a secondimpeller like that defined in claim 2, the two impellers beingintegrally formed with their respective maximum diameters at rightangles to each other and with an integral disc between them having adiameter equal to said maximum diameter; said instrumentalitiesincluding a second oscillating member bearing against the periphery ofthe second impeller and traversing a portion of said partition adjacentto that-traversed by the other oscillating member, said members beingpivotally mounted on opposite sides of said support.

8. The combination set forth in claim 7 in which each of said membersincludes a hub, the members being pivotally mounted by means of a shaftpassing through both members and through the intervening support, thetotal axial distance across the two hubs when mounted on said shaftbeing only slightly less than the distance between said end plates, theportions of the oscillating members that traverse the partition being soconstructed and located with respect to the hubs that each isautomatically positioned between said disc and a different one of saidend plates.

9. The combination set forth in claim 2 with the addition of a pluralityof at least partially removable dowels each extending both into saidcylindrical body and into said rear plate.

10. The combination set forth in claim 9 with the addition of aplurality of bolts each passing through said front plate, then axiallythrough the wall of said cylindrical body, thence through said rearplate, and finally anchored in said housing to clamp them all together.

11. The combination set forth in claim 2 in which the bearing structurecomprises a housing, said housing adjoining said rear plate, saidbearing housing having blind holes therein opening toward said casing,said blind holes threaded near their inner ends and provided at theirouter ends with counterbores of the same diameter as those in saidcasing, said holes in said housing positioned to align with those insaid plates and casing; and to which said combination is added aplurality of dowel-bolts individual to the holes in said housing, eachof said dowel-bolts having (a) a first section threaded into thethreaded portion of one of the holes in said housing, (b) a secondsection adjacent said first section and having substantially the samediameter as said counterbores, said second section extending through thecounterbore adjacent the threaded portion of the hole into which thedowel-bolt is threaded, then through an aligned hole in said rear plateand into an aligned counterbore in said casing, (c) a third section ofreduced diameter extending from the last mentioned counterbore throughthe remainder of the hole in the casing and then through an aligned holein said front plate, and (d) a threaded end at least a portion of whichprotrudes through said front plate for threaded engagement with aclamping nut.

12. The combination set forth in claim 3 in which one of said collars isformed of carbon and the other of ceramic material to minimize thefriction therebetween.

13. The combination set forth in claim 3 in which the 2 bearingstructure comprises a housing, said housing having a circularcompartment in the Wall thereof surrounding said shaft but spacedtherefrom and adjoining said casing; and a guard member comprising aband and a flange, said band gripping said shaft within said opening insaid casing, and said flange extending into said chamber and acting todeflect therein whatever fluid from said casing may escape beyond saidcollars.

14. The combination set forth in claim 12 in which there is an annulargroove in the casing extending radially from said circular opening andan O-ring nesting in said groove and embracing said shaft to serve as anadditional seal against the escape of material from said casing throughsaid opening.

15. The combination set forth in claim 13 in which there is an annulargroove in the casing extending radially from said circular opening andan O-ring nesting in said groove and embracing said shaft to serve as anadditional seal against the escape of material from said casing throughsaid opening.

16. The combination set forth in claim 3 with the addition of anelongated metal cap for slidably encasing the unsupported end of saidshaft, said cap comprising a sleeve portion keyed to said shaft andextending through said opening, the impeller being bonded to said cap,said casing having an annular groove therein extending radially fromsaid circular opening and said sealing instrumentalities comprising anO-ring nesting in said groove and embracing said sleeve.

17. The combination set forth in claim 16 in which the cap thatcomprises a sleeve is a cylindrical tube with its periphery, theinternal surface of the casing surrounding said opening beingsubstantially flat, and having first and second grooves therein, saidfirst groove positioned above said central opening and said secondgroove positioned below said opening, both of said grooves communicatingwith the conical surface of said second collar via the portion of theend of the impeller that is surrounded by said rim, said first grooveextending vertically above the portion of said internal surface that istraversed by said impeller and said second groove extending downwardsufliciently for its lower end to be exposed only between said spacedperipheral portions of the impeller, said grooves acting when the casingis being flushed to entrain cleaning fluid through said first groove andexpel it from the bottom of said second groove.

20. The combination set forth in claim 16 in which the impeller containsa solid, non-elastomeric core to give it substantial rigidity anddimensional stability.

21. The combination set forth in claim 3 in which the bearing structurerecited in claim 1 comprises an external member having a generally flatsurface at least a portion of which is in contact with the adjacentsurface of said rear member; there being a passageway in at least one ofsaid members leading generally upward from the bottom thereof towardsaid shaft to afford a drain for flowable material that may escapethrough said sealing instrumentalities.

22. The combination set forth in claim 16 with the addition of a sealingring encircled by an annular shoulder protruding from the surface of thebearing structure of claim 1 that adjoins said casing, said sealing ringembracing the portion of said sleeve that extends through said O-ring,said sealing ring acting as a seal for the bearing.

23. The combination set forth in claim 3 in which the end of the casingopposite from said opening has a flat inside surface and in which atleast all the external surface portions of said impeller are formed ofelastomeric material, and there being an axially extending rim aroundeach end of the impeller adjacent its periphery, the internal surfacesof each end of the casing being swept by the rim of the adjacent end ofthe impeller and having first and second grooves therein, the upper endsaid first groove extending above the portion of said internal surfacethat is traversed by said rim and the lower end of said second grooveextending downward suflicently to be exposed only between said spacedperipheral portions of the impeller, both of the first grooves actingwhen the casing is being flushed to entrain cleaning fluid and conductit into the spacial area encompassed by said rim, and both of the secondgrooves acting to drain said fluid from said area.

24. The combination set forth in claim 6 in which the end of the casingopposite from said opening has a flat inside surface and in which atleast all the external surface portions of said impeller are formed ofelastomeric material, there being an axially extending rim around eachend of the impeller adjacent its periphery, the internal surface of theend of the casing having the central opening therein being swept by therim of the adjacent end of the impeller, the end of the impelleradjacent the opposite end of the casing having a central boss extendingbeyond the surrounding rim and substantially engaging the end of thecasing adjacent thereto, the boss acting to limit the movement of theimpeller in one axial direction and the tolerance accumulation deviceacting to limit the movement of the impeller in the opposite axialdirection.

25. The combination set forth in claim 4 in which the second portion ofsaid recess has a plurality of arcuate sides whose radii are eachgreater than the greatest distance from the associated side to the axisof the shaft, and in which said projection has a peripheral contour thatmatches the arcuate sides of the second portion of said recess.

15 26. The combination set forth in claim 4 in which the second portionof said recess has cylindrical Walls that are eccentrically disposedwith respect to said axis and in which said projection has a cylindricalperiphery that nests Within the second portion of said recess.

References Cited by the Examiner UNITED STATES PATENTS 16 Hinckley103-124 Chapman 103-136 Hinckley a- 103-124 Nebel 103-124 Adams et a1.103-217 Hinckley 103-124 Conover 103-136 Hin-ckley 103-124 10 DONLEY J.STOCKING, Primary Examiner.

W. J. GOODLIN, Assistant Examiner.

1. IN A ROTARY PUMP COMPRISING A CASING HAVING A CIRCULAR OPENING FOR ASHAFT AND OPPOSITELY DISPOSED INLET AND OUTLET PORTS THERETHROUGHCOMMUNICATING WITH A CHAMBER THEREIN A PORTION OF WHOSE WALLS MOSTDISTANT FROM SAID PORTS ARE CONCENTRIC WITH SAID OPENING, A COMBINATIONINCLUDING: A DRIVE SHAFT CONCENTRIC WITH SAID OPENING EXTENDINGTHERETHROUGH INTO SAID CHAMBER AND TERMINATING THEREIN; A BEARINGSTRUCTURE FOR SAID SHAFT DISPOSED EXTERIORLY OF SAID CHAMBER, THE END OFSAID SHAFT WITHIN SAID CHAMBER BEING FREE FROM SUPPORT; A REMOVABLEIMPELLER ENTIRELY CLOSED AT ONE END AND HAVING A RECESS IN ITS OTHER ENDTHAT SLIDABLY RECEIVES THE UNSUPPORTED END OF THE DRIVE SHAFT; MEANS FORKEYING SAID IMPELLER TO SAID SHAFT FOR ROTATION THEREWITH; SAID IMPELLERHAVING SPACED PERIPHERAL PORTIONS THAT SWEEP SAID CONCENTRIC PORTION OFSAID WALLS; AND INSTRUMENTALITIES INTERPOSED BETWEEN SAID PORTS FORDIRECTING THE INFLOW FROM SAID INLET PORT TOWARD SAID CONCENTRIC PORTIONOF THE WALLS WHEREBY SAID INFLOW MAY BE MOVED ALONG SAID PORTION OF SAIDWALLS TOWARD SAID OUTLET PORT BY SAID SPACED PERIPHERAL PORTIONS.